TUESDAY, July 23 (HealthDay News) -- Americans who live in cities are less likely to die from accidental injuries than those who live in rural areas, a new study says.

The findings challenge the widely held belief that cities are more dangerous places to live than rural areas, according to the researchers.

The study authors analyzed data on all injury deaths across the United States from 1999 to 2006, but did not include deaths from the Sept. 11, 2001 terrorist attacks, due to their unusual nature.

The top three causes of death nationwide were traffic crashes, guns and poisoning. Overall, the risk of injury-related death was about 20 percent lower for people in urban areas than for those in rural areas, and 40 percent lower for people in the largest cities than for those in the most rural areas.

The study found that murder rates were lower in rural areas than in urban areas, except among adults older than 65. Suicide rates were higher in rural areas, but the higher suicide rate only reached statistical significance for children and teens up to 19 years old.

The nationwide rate of injury-related death was more than 15 times higher than that of murder, according to the study, published online July 23 ahead of print in the journal Annals of Emergency Medicine.

Traffic crashes accounted for most of the accidental injury deaths nationwide, with a rate 1.4 times higher than the next leading cause of injury-related death. In rural areas, the rate of deaths from injuries suffered in traffic crashes was two times higher than the next leading cause of injury-related death.

The researchers also found that people in rural areas were two times more likely to die from traffic crash-related injuries than those in the largest cities.

"Perceptions have long existed that cities were innately more dangerous than areas outside of cities, but our study shows this is not the case," study lead author Dr. Sage Myers, assistant professor of pediatrics at the University of Pennsylvania Perelman School of Medicine, said in a university news release.

"These findings may lead people who are considering leaving cities for non-urban areas due to safety concerns to re-examine their motivations for moving. And we hope the findings could also lead us to re-evaluate our rural health-care system and more appropriately equip it to both prevent and treat the health threats that actually exist," added Myers, an attending physician in the emergency medicine department at Children's Hospital of Philadelphia.